Assessment of patented coronary end-to-side anastomotic devices using micromechanical bonding

Background. Despite multiple patented ideas for vascular end-to-side anastomotic devices, and the growing need for them in minimally invasive coronary bypass procedures, no device has been evaluated clinically yet. This study assessed patents of micromechanical end-to-side anastomotic devices with respect to application in coronary artery bypass grafting. Methods. Patents were categorized with respect to their micromechanical bonding principle. Calculated values for the wall strain during the construction of an anastomosis were compared with the allowable strain for human coronary arteries. Results. From 51 patents describing vascular anastomotic devices, 11 ideas, categorized into four groups (staples, clips, mounting systems, and intraluminal stent structures), are serious candidates for coronary end-to-side anastomoses. Most ideas use an anvil for proper application of the bonding elements. For small (1.5 mm) coronary arteries, the calculated wall strain was 0.87, exceeding the breaking strain (0.45) in 60- to 79-year-old patients. Conclusions. In a coronary anastomotic device, the concept of using an anvil for the application of micromechanical bonding elements is not attractive, because excessive wall strain is likely to occur.